Predicting acoustic performance in reconfigurable classrooms.

Abstract

A tour of the new ETS-Lindgren Acoustic Research Laboratory in Cedar Park, Texas will be conducted. The schedule for the day includes a technical discussion on acoustic test facilities followed by a lunch break and factory tour. As a bonus, the tour will feature demonstrations of the material presented in the technical discussion.Tour participants will see several state-of-the-art chambers for acoustic test services, including a hemi-anechoic chamber and two reverberation chambers, impedance tubes and supporting acoustic test equipment and software. The laboratory offers product noise emission testing and structural/architectural acoustic testing.Product noise emission testing is commonly performed in the double-walled hemi-anechoic chamber that is designed to measure very low noise emissions from products and devices at 80 Hz and above Outside chamber dimensions are 8.5 m long ϫ 8.5 m wide ϫ 7 m high. This chamber is ideal for testing sound power and pressure levels as well as small fan noise. Products tested include Information Technology Equipment ͑ITE͒ such as laptop computers and associated printers, home appliances, garden equipment -essentially any noise emitting device may be tested in this chamber. Commonly referenced standards for testing in this chamber include ISO 3744, SO 3745, ISO 7779, ISO 11201, and ECMA 74. Structural/architectural acoustic testing is performed in the reverberation chambers. With transmission loss testing of wall samples, windows, doors, automobile panels and the like, design engineers can determine how much sound energy is transmitted through a product in the chambers. The source chamber measures 7.4 m long ϫ 5.9 m wide ϫ 4.8 m high; the receive chamber measures 7.4 m long ϫ 9.2 m wide ϫ 6 m high. ASTM E90, ASTM C423, ASTM E596, and ISO 3741 are the most commonly referenced standards for testing in these chambers.To enhance chamber performance, the hemi-anechoic inner chamber sits on a 50 ton isolated concrete slab while the reverberation chambers sit on individual floating concrete slabs. The laboratory is ISO 17025 accredited under the US Department of Commerce NIST National Voluntary Laboratory Accreditation Program ͑NVLAP͒ Lab Code 100286-0. The tour will also feature a stop in ETS-Lindgren's ISO 9001 certified factory. Tour participants will see how acoustic chambers are constructed.Bus loading will begin promptly at 8:00 am outside the main entrance of the Hyatt Regency Hotel, on Losoya Street. Tour participants will travel in a luxury air-conditioned motor coach for approximately 90 minute ride to Cedar Park ͑near Austin͒. The bus is equipped with bathroom facilities. Refreshments will be provided upon arrival at ETS-Lindgren. A traditional Texas Style BBQ lunch buffet will be served at noon. Snacks in the afternoon and a treat for the return bus ride to San Antonio will also be provided. The bus will depart Cedar Park by 2:30 pm for an arrival at the Hyatt Hotel before 5:00 pm, traffic permitting. Please note tour attendance is limited to 50 people and reservations will ...